PUP.Optional.Wajam is the detection name for Wajam, a browser add-on marketed as a “social search.”
This is a generic detection applied when a PUP blocks another program from running by intercepting it using the Image File Execution Options (IFEO) registry key.
You can read more about this registry key on our blog in the post, An Introduction to Image File Execution Options.
Image File Execution Options are used to intercept calls to an executable. Its intended use is for debugging or replacing applications, but using it as a means to simply stop the executable from executing altogether has been common practice as well.
Malwarebytes completely removes this threat. No further cleanup is required.